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J/AJ/118/2014 Nearby poor clusters of galaxies catalog (White+, 1999)
A catalog of nearby poor clusters of galaxies
White R.A., Bliton M., Bhavsar S.P., Bornmann P., Burns J.O.,
Ledlow M.J., Loken C.
<Astron. J. 118, 2014 (1999)>
=1999AJ....118.2014W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxy catalogs ; Redshifts ;
Cross identifications
Keywords: catalogs - galaxies: clusters: general
Abstract:
A catalog of 732 optically selected, nearby poor clusters of galaxies
covering the entire sky north of -3° declination is presented. The
poor clusters, called WBL clusters, were identified as concentrations
of three or more galaxies with photographic magnitudes brighter than
15.7, possessing a galaxy surface overdensity of 104/3. These
criteria are consistent with those used in the identification of the
original Yerkes poor clusters, and this new catalog substantially
increases the sample size of such objects. These poor clusters cover
the entire range of galaxy associations up to and including Abell
clusters, systematically including poor and rich galaxy systems
spanning over 3 orders of magnitude in the cluster mass function. As a
result, this new catalog contains a greater diversity of richness and
structures than other group catalogs, such as the Hickson and Yerkes
catalogs. The information on individual galaxies includes redshifts
and cross-references to other galaxy catalogs. The entries for the
clusters include redshift (where available) and cross-references to
other group and cluster catalogs.
File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file
table2.dat 112 732 Poor-cluster catalog
table3.dat 90 3324 Poor-cluster galaxies
table4.dat 19 219 Previous Nomenclature
See also:
VII/26 : Uppsala General Catalogue of Galaxies (UGC) (Nilson 1973)
VII/49 : Galaxies and Clusters of Galaxies (CGCG) (Zwicky, 1968)
VII/118 : NGC 2000.0 (Sky Publishing, ed. Sinnott 1988)
VII/190 : Zwicky Galaxy Catalog (Zwicky+ 1968)
VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)
VII/213 : Hickson's Compact groups of Galaxies (Hickson+ 1982-1994)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 7 A7 --- WBL WBL cluster designation (WBL NNN)
9- 10 I2 h RAh Cluster centroid right ascension (B1950.0)
11- 14 F4.1 min RAm Cluster centroid right ascension (B1950.0)
15 A1 --- DE- Cluster centroid declination sign (B1950.0)
16- 17 I2 deg DEd Cluster centroid declination (B1950.0)
18- 19 I2 arcmin DEm Cluster centroid declination (B1950.0)
21- 23 I3 --- Rich Richness (number of CGCG galaxies in each
poor cluster)
25- 43 A19 --- Clust. Clustering at sigma_46_ (1)
45- 51 F7.5 --- z ? Poor-cluster redshift (2)
53- 55 I3 --- o_z ? Number of galaxy redshifts available from NED
57- 59 A3 --- n_z Notes on z (3)
61- 71 A11 --- ZWCL Zwicky cluster containing the given WBL cluster
within its contours
72- 73 A2 --- n_ZWCL [MD ] MD: medium-distant cluster
75- 77 I3 arcmin RZ ? Radius of the Zwicky cluster
79- 82 F4.2 --- fZ ? Distance separating the center of the Zwicky
and WBL clusters, in units of the Zwicky
cluster radius (4)
84- 87 I4 --- ACO ? Abell cluster cross-correlation (5)
89- 91 I3 --- CfA ? CfA (<VII/193>) group cross-correlation (6)
93- 95 I3 --- HCG ? HCG (<VII/213>) cross-correlation (7)
98-112 A15 --- Yerkes Yerkes cluster cross-correlation (8)Note (1):
An indication of the fate of each individual galaxy at the higher
density enhancement (σ46). A single zero in this column
indicates that a group at σ21 fractured into single galaxies
at σ46 (i.e., the galaxy apertures did not overlap).
Combinations of other numbers indicate how many galaxies were in each
subcluster at σ46, with "0" indicating one or more isolated
galaxies. For example, a cluster with 11 members and an 8+0 in this
column becomes a group of eight members with three isolated galaxies
at σ46. A cluster of 11 members and an entry of 4+3+2+0 breaks
up into three subclusters of four, three, and two members, with two
isolated galaxies at σ46.
Note (2):
Redshift for the cluster, when available, computed as an average of
redshifts from the literature obtained through the NASA Extragalactic
Database (NED).
Note (3):
If there is no note, the number of galaxy redshifts were used to
compute the cluster redshift.
i: there were only two redshifts available and their values differed
by more than 1500km/s. n this case, the two galaxies may be close
only in projection. The redshift given in this case is the average
of the two galaxy redshifts.
ii: Of the three or more redshifts available, one was more than
1500km/s from the mean. After removing this discrepant redshift, a
new mean was calculated, with all remaining redshifts within
1500km/s from this new mean.
iii: Of the three or more redshifts available, at least two discrepant
redshifts were present. The redshift listed is then the mean
redshift calculated after removing only the most discrepant
velocity. A value of 1500km/s was chosen for the cutoff velocity
because a "typical" poor cluster has a velocity dispersion of
∼500km/s. This criteria is thus analogous to the standard 3σ
lipping often used in the literature.
Note (4):
The radius is that given in the CGCG and is meant to indicate the area
on the sky contained within the hand-drawn contours. Zwicky clusters
are rarely spherical, so all correlations were verified by eye. Zwicky
clusters are also separated into estimated distance classes, with near
clusters meant to be in the redshift range 0.0<z≤0.05 and
medium-distant clusters in the range 0.05<z≤0.1 (CGCG). We included
any near or medium-distant Zwicky cluster that contained a WBL cluster
within its contours. Near clusters were chosen over medium-distant
clusters in the very few cases where a poor cluster fell within the
boundaries of two Zwicky clusters of different distance classes.
Note (5):
Any WBL cluster located within one corrected Abell radius of a
distance class 3 or nearer Abell cluster was considered associated
with the Abell cluster. In addition, NED was used to search for WBL
cluster members that were also members of Abell clusters.
Note (6):
Associated CfA groups were identified as groups whose coordinates were
within 30' of the WBL centroid.
Note (7):
Associated Hickson compact groups were identified from information on
individual galaxies obtained through NED.
Note (8):
The identification of WBL clusters associated with the Yerkes clusters
(AWM (Albert et al., 1977ApJ...211..309A, MKW (Morgan et al.,
1975ApJ...199..545M) and WP (White, 1978ApJ...226..591W)) was
determined visually as a part of the development of the WBL catalog.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 7 A7 --- WBL WBL cluster designation (WBL NNN)
8- 11 A4 --- gal [-0-9] Galaxy designation in WBL NNN (-NNN)
13- 14 I2 h RAh Right ascension (B1950.0) (1)
16- 17 I2 min RAm Right ascension (B1950.0)
19- 20 I2 s RAs Right ascension (B1950.0)
22 A1 --- DE- Declination sign (B1950.0)
23- 24 I2 deg DEd Declination (B1950.0)
26- 27 I2 arcmin DEm Declination (B1950.0)
29- 32 F4.1 mag Pmag Galaxy apparent photographic magnitude (1)
34- 36 I3 --- N21 ? Nearest neighbors (2)
38- 39 I2 --- N46 Nearest neighbors (2)
41 A1 --- Clust. Clustering atsigma_46_ (3)
43- 49 F7.5 --- z ? Redshift of the galaxy reported in NED (4)
51- 90 A40 --- Names Galaxy catalog cross-correlations (5)Note (1): Data from the CGCG (Cat. VII/49)
Note (2):
Measure of the number of nearest neighbors to the galaxy at
σ21 (N21) and σ46 (N46). This refers to the number of
neighbor galaxies falling within the aperture defining the σ21
or σ46 threshold. For a galaxy with no nearest neighbor, the
aperture radius is 0.084° at σ21 and 0.057° at
σ46. The radius scales as (n+1)1/2, where n is the number of
nearest neighbors. For an individual galaxy, the higher the number,
the more centrally located it is within the poor cluster. Multiple
poor-cluster members with high numbers of neighbors indicate a compact
cluster. Galaxies with a nearest neighbor number of zero were merged
into a cluster because a nearby galaxy possessed many neighbors. The
resulting large aperture [∝(n+1)1/2] may have overlapped an
isolated galaxy in some cases.
Note (3):
An indication of the fate of each individual galaxy at the higher
density enhancement. A blank field indicates that the galaxy became
isolated (no neighbors and no overlapping apertures) and therefore was
not considered a member of a cluster at σ46. Galaxies with the
same letters are part of the same poor cluster at σ46. WBL
designations for these subgroups should include this letter and
indicate that it is a σ46 cluster.
Note (4):
Several Zwicky galaxies are actually multiple galaxies and therefore
have multiple identifications in NED. In these instances, the average
of all redshifts available for the Zwicky galaxy is presented.
Note (5):
Cross identifications for the galaxies from the NGC, IC (See Cat.
VII/118) and UGC (Cat. VII/26) catalogs obtained from NED. For
entries that are actually multiple galaxies, all relevant
identifications are presented.
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Identification (1)
10- 16 A7 --- WBL WBL designation
18- 19 A2 --- Note [abc ] Note when no WBL poor cluster
associated with a Yerkes cluster (2)
Note (1):
This table cross-references the names of the poor clusters presented
here with previous names used in the literature. We also present a
direct comparison of the WBL clusters with the Yerkes (AWM (Albert et
al., 1977ApJ...211..309A, MKW (Morgan et al., 1975ApJ...199..545M) and
WP (White, 1978ApJ...226..591W)) poor clusters. We list every Yerkes
poor cluster along with any corresponding WBL cluster.
Note (2):
a: Cluster galaxies were too faint to be included in the WBL catalog.
b: Cluster is too diffuse to meet the galaxy density criterion of the
WBL catalog.
c: Cluster is south of -3° declination and therefore not included
in the WBL catalog.
History: From AJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 10-Jan-2000